The present invention generally relates to devices for connecting two transmission cables each comprising, beneath a protective jacket, a plurality of cable elements. More specifically, the invention is concerned with a device for connecting two optical fiber cables for installation on site, i.e. for example in a cable tunnel, where the cable elements are spliced.
Processes and devices are already known which make it possible to splice two cable elements each having, beneath a protective jacket, a dielectric cylindrical support reinforced along its axis and provided with grooves, which are either longitudinal or helical having a single or alternating pitch, regularly distributed over its circumference and whereby each houses and optical fiber. Reference can be made for example to European Patent Application filed by the Assignee and published on Sept. 23, 1981 under No. 36,369 for : "Process and apparatus for connecting on site optical fiber cables". According to this patent application, the process of splicing two optical fiber cable elements consists of carrying out on a so-called splicing bench the connection and then alignment of two extending end fittings serving as connectors and integral respectively with the two cable elements. These operations are relatively difficult to perform and generally require considerable skill on the part of the operator.
Moreover, when it is necessary to connect two optical fiber cables on the actual site, it is necessary to position the connecting device in a very careful manner, so as to enable the operator to make the various splices on the optimum working conditions. In addition, the installation of the connecting device must contribute to reducing the duration of the connecting operation. Furthermore, once the cable elements have been spliced, they have to be arranged in an ordered manner within a tight box or case, so that in the case of a fault on the part of one of the cable elements, the operator can obtain rapid access thereto.
The object of the present invention is to make it possible to fulfil the aforementioned objectives by proposing a connecting device for two optical fiber cables, which is particularly suitable for installation on site.
To this end, the present invention relates to a device for connecting on site two optical fiber transmission cables each comprising at least one cable element, wherein the device comprises:
a table to be installed in an on site tunnel and which has a notch on its circumference;
a tight splicing box for protecting the two cable elements once they have been connected together and fitted so as to be supported on the table, the two lateral faces of said box having two openings in which are engaged respectively the two cables to be connected;
a splicing bench which can be inclined and positioned in the table notch, including a rail disengaged from the box and facing the latter and on which are arranged tools used for splicing the two cable elements; and
means for joining the bench to the table such that bench and table together form a rigid unit.
According to another feature of the invention, the splicing box incorporates a member in the form of a drum having longitudinal grooves and two members forming annular collars fitted at the two ends of the drum and each provided with slots distributed over the periphery thereof. Each cable element traverses the drum, whilst resting in one of its grooves and is then positioned, whilst forming a loop, in a slot of one of the two collars. Under these conditions, each cable element is arranged in an ordered manner within the box and the loop path followed by said element makes it possible to have an extra cable length, which is particularly advantageous for recommencing a splice which is considered to be defective .